Earth-drill.



EARTH) DDDD L.

. APPLICA 917- n 1,287 280. v Patented Dec. 10, 1918.

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UNITED gTATES PATENT @FFICE.

ROBERT E. FRONK AND CHARLES E. KERSEY, 0F KEWANEE, ILLINOIS.

EARTH-DRILL.

Specification of Letters Patent.

Application filed January 3,1917. 7 Serial No 140,394.

T 0 all whom it may concern I .Be it known that we, ROBERT E. FRoNK andCHARLES E. KnnsEY, citizens of the United States, residing at Kewanee,in the county of Henry and State of Illinois, have invented certain newand useful Improvements in Earth-Drills, of which the following is aspecification.

This invention relates to an improvement in earth drills andparticularly to means for locking the points to the ends of drill rods,and to this end it consists in providing the lower end of the drill rodin addition to the tapered internal thread with a plurality of slotsarranged concentrically with the axis of the drill rod and havinginclined bottoms and in connection with said slots to fit the drillpoint with a plurality of screws extending upwardly therethrough at anangle and adapted to project from the point after the latter has beensecured into place in the end of the drill rod, into said slots for thepurpose of holding the point against rotation relatively to the drillrod.

With the above as the main object in view the invention consists of thenovel construction, combination and arrangement of parts hereinafterdescribed pointed out in the appended claims, and illustrated in theaccompanying drawings, in which Figure l is a longitudinal centralsection throu h the lower end of the drill rod and a drill pointconnected thereto and locked vagainst rotation,

Fig. 2 is a cross sectional view on the line 22 of Fig. 1,

Fig. 3 is an end view of the drill point.

In the drawing, 10 indicates the lower end of a drill rod which is ofindefinite length, said lower end being formed with an axial recess, thewalls of which are tapered in-h wardly and threaded as shown at 12 toen- 'gage the similarly threaded truncated upper end 13 of the drillpoint 14'. The bottom 15 of the recess 11 has formed therein two or morecurved slots *16 that are made concentric with the axis of the drill rod10 and separated from each other by radial walls 17. Each slot 16 hasits bottonifiinclined and one end, formed by the fiat face of a wall17,. perpendicular to the bottom 15 of the tapered and threaded recess11. From this end the bottom of the slot-inclines outwardly, its otherend terminating at the outer end of another wall 17 flush with thenotches each having an end perpendicular and a bottom inclined to thebottom of the recess.

The drill point 14 just below the threaded portlon 13 is preferably ofthe same diameter as the drill rod 10 but said drill point lower downtapers inwardly at 19 to the point proper 20.

Extending upwardly through the drill polnt 14 from the tapered portion19 through the upper end of the threaded "portion 13 are a number oflong screws 21, the upper ends of said screws inclining toward the axisof the drill point and projecting at their upper ends into the notches16 in the drill rod 10, the ends of these screws, which are shown equalin number to the number of notches 16, bear upon the inclined bottoms ofsaid. notches or against the straight sides 18 of the walls 17 and lockthe drill, point against rotation. These screws 21 have heads 22 ontheir lower ends by means of which they may be backed out of. thenotches 16 when the drill point is to be removed from the rod 10 andadvanced to their limit of movement so that their points will enter andengage in the slots 16. The heads 22 of these bolts fit in recesses 23formed in the tapered portion 19 of the drill point and are thusiout ofthe way of the point when operating as a. drill. Preferably two screwsonly are used placed diametrically on opposite sides of the axis of thedrill point. These two screws in connection with three notches in thedrill rod 10 will enable at least one of said screws to always engageone of the notches and thereby prevent rotation of the drill point. 1

'What we claim is:

1. In a device of the class described, a drill rod, a drill pointthreadedat one end into-a recess in the end of the drill rod, and ascrew threaded into said point in alongitudinal direction and convergingtoward the axis of the drill point to be projected by r0- tation fromthe threaded end of said point into one of a series of curvedconcentrically alined slots in the bottom of said recess for locking thepoint in any position against backward rotation.

Patented Dec. 10, 1918.

2. In a device of the class described, a

drill rod having a threaded recess in one end, a drill point providedwith a threaded projection engaging said. recess, a plurality of alinedarc-uate slots concentrically disposed in the bottom of said recess andhaving bottoms inclined at an angle to the bottom of the recess, and abolt threaded longitudinally through the drill point from the exteriorand converging toward the comr'ion axis of the drill rod and point to beprojected by rotation from the end of the threaded projection of saidpoint for engaging one 0t said slots to lock the point to the drill rodin any relative position 01" rotation and prevent backward movement ofthe drill point.

3. In a device of the class described, a drill rod having a threadedrecess in its lower end and a plurality of alined curved slotsconcentrically arranged about the axis memeo of said rod at the bottomof said recess, each slot having a bottom inclined at an angle to thebottom of the recess, a drill point having threaded extension on one endengageable with the threaded recess in the drill rod, and a plurality ofbolts threaded longi-

